Posted by Bruce in BC [108.162.244.103] on Thursday, January 07, 2016 at 21:48:06 :
In Reply to: Castle Nut posted by Bob in N. GA [173.245.50.142] on Thursday, January 07, 2016 at 21:40:41 :
Most likely "National Screw"
NC , NF and NS are the norm.
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